But outside the organization, the Celtics have been viewed as nothing short of a pleasant — if not shocking — surprise as they’ve reached the quarter mark of a rebuilding season. The Celtics get a national television audience on Friday night (ESPN) when they host the Nuggets.

“I would have never said, ‘They’ll be 8-12 at this stage.’ I would’ve never said that,” said ESPN analyst and former NBA head coach P.J. Carlesimo. “It’s just asking too much, without Rajon [Rondo] right now.”

Carlesimo, who has been on the Comcast SportsNet broadcast team for several Celtics games this year, added that with Rondo (knee) sidelined and Kevin Garnett and Paul Pierce both traded to Brooklyn, the Celtics’ ability to be consistently competitive while leading the division at this point is simply “incredible.”

“I’ve been very, very impressed with what they’ve done so far,” Carlesimo said. “They continue to surprise me, to be honest with you. I really, really like the team. I really like the way they play.”

Granted, the Atlantic Division is awful, he noted. And the Celtics still have issues.

“They struggle to score — that’s the big problem,” he said. “They really struggle to score and they struggle with size.”

The Celtics have also had issues with rebounding (41.4 per game, 20th in the league entering Thursday) and turnovers (16.6 per game, 24th in the league).

“But they’re just so much better defensively than they are offensively, which is a good trait, and that keeps them in games,” Carlesimo said.

The Celtics have the league’s seventh-best scoring defense, allowing just 96.8 points per game, but they have the 25th-worst offense, scoring just 93.8 per game.

Around the league, Carlesimo said the general view is, “Wow, the Celts are doing a lot better than I thought they would do.” He added, “They would say that Brad and the staff have done an excellent job, a way, way above-average job.”

Carlesimo, who made his NBA head coaching debut in 1994 and coached the Brooklyn Nets last season, also pointed to the fact that of the 13 head coaches in their first year with their new teams, Stevens has been the most consistent, other than losing the first four games.

Fellow ESPN analyst George Karl, an NBA head coach for 25 seasons, said he has been impressed with Stevens, even though Karl hasn’t always been sold on college coaches leaping to the NBA.

“I remember sitting back when it happened and I said, ‘Why do I think this is a good decision, because I’m usually against hiring the college coach?’ ” Karl said. “And I don’t know if it’s Brad’s personality from the standpoint that he seems to be a very humble guy. He’s somewhat of a quiet guy. And a lot of college coaches have much more ego.”

Karl added, “I think what my mind is telling me is that the game is going through some change, from analytics to how we’re coaching the team. And basically as a coach, you’ve got to be able to adapt and maneuver what you believe to the circumstances and the roster and the opportunities you have.”

Karl said he hasn’t watched many Celtics games this season, but from what he has seen, he has enjoyed watching Stevens grow.

“He almost reminds me of watching a young player,” Karl said. “You can almost see the light switch go on. I think he’ll become more comfortable. He’ll become more aggressive.”

Carlesimo praised how Stevens has incorporated young players into the lineup, such as Kelly Olynyk, Vitor Faverani, and Phil Pressey. “Some of them by design, some of them as a result of all these injuries, but they’ve all been good,” Carlesimo said.

It can’t be overlooked how other players have stepped up to fill the void left by Garnett, Pierce, and even Rondo, Carlesimo added.

“Any time you lose one of the elite players — and they lost three — it just bumps everybody up,” he said. “That’s always been something that sometimes the average fan doesn’t see.”

Players who were used to playing complementary roles now have to carry a much bigger load, perhaps as a starter.

“And this team has hung in there extremely well,” Carlesimo said “They play very, very hard. They’re very competitive — competitive in the sense that they get after people.”

Some Celtics fans have been more than a little upset over the number of wins this season, as they’d rather their team lose — i.e. “tank” — to potentially land a top draft pick in 2014.

“The Celtics should know better than any franchise, there’s no guarantee where you finish with who you’re going to get. You can go all the way back to the Tim Duncan year,” Carlesimo said, referencing the Celtics’ 1996-97 season, when they finished 15-67 (second-worst in the league) but didn’t land the top draft pick.

“Players and coaches aren’t going to do that,” Carlesimo added. “That’s more of a front office thing. I just don’t subscribe to that. I just know players and coaches are going to try and win games, period. There’s no question about that.

“To me, the Celtics fans should be more proud of how competitive this team has been and continues to be and the improvement of the young players.”